Date of Graduation
Statler College of Engineering and Mineral Resources
Petroleum and Natural Gas Engineering
The treatment of produced water as a fracturing fluid is becoming an increasingly important aspect of water management surrounding the booming of the unconventional oil and gas industry. Two main problems facing the oil and gas industry are the availability of water for well drilling and completion and disposal of the produced water. Unconventional well drilling and completion in the Utica shale requires large amounts of water. The wastewater that results after production—containing high levels of organic and inorganic matter— is usually disposed of through deep well injection. A new approach reuses this produced water as part of subsequent fracturing fluid, an alternative that could significantly reduce both fresh water demand and the cost associated with disposal. Produced water is typically only treated for a limited number of constituents, so understanding variation in water quality due to fracturing fluid and produced water age are fundamental to choosing an effective treatment strategy. Multiple cost-effective produced water treatment methods have been developed but limited research has been done to understand produced water production volumes and quality from oil and gas fields. Accurate predictions of produced water volumes and quality from a shale gas field is important to plan long term recycle strategies, model availability of water resources, and optimizing designs and siting of water handling and treatment facilities.
This study aims to first establish a spatial and temporal water quality analysis, and the optimization of the produced water recycle program from Gulfport Energy shale gas wells in Belmont County, Ohio. 220 produced water samples were collected from January 2015 to April 2016; pH, TDS, chloride, sulfate, magnesium, manganese, iron, strontium, barium, calcium, and sodium were measure at X-Chem laboratory, WV. All the produced water samples were acidic with pH ranging from 4.8 to 6.1. TDS, cation, and anions tested in our study varied greatly. Linear and logarithmic spatial correlation made for TDS, chloride, sulfate, strontium, barium, sulfate, magnesium, manganese, calcium, and sodium were shown, which made it possible to estimate unknown parameters. Spatial and temporal trends of TDS, chloride, sulfate, strontium, barium, sulfate, magnesium, manganese, calcium, and sodium, with inner relationships of ion concentrations, could allow us to make predictions of produced water qualities. The iron concentration, however, closely correlates with geological formation, so the iron concentration of produced water must be determined spatially as an average value and maximum value in each Integrated Development Plan. A framework for optimizing produced water reuse is presented as part of this study. Typically, depending on the frac fluid quality required and blending ratio, produced water will be treated to meet recycled water quality required. In this study coagulation/filtration, and microfiltration were used for removal of suspended solids, oil and grease, and turbidity of produced water. The proper amount of fresh water needed to blend with the produced water must be determined. With sources of fresh water limited, the amount of water used to optimize the recycling of produced water is one of the most significant issues in the management of produced water. Calculating the quantity of fresh water necessary can be based on the quality of the fresh water, fracturing fluids and the targeted quality of the recycled water; in some cases, it might be based on the quantity of fracturing fluids and recycled water targeted. If the result based on quality is not less than the quantity-based result, additional treatment will be required. Produced water quality analysis of the horizontal wells in the Utica and the established produced water recycling system program are supporting produced water management and the viability of produced water reuse.
Mbakop, Armel Quentin, "Predictions of Produced Water Quality and Recycled Water Optimization for Spatially-Distributed Wells in Point Pleasant Formation" (2022). Graduate Theses, Dissertations, and Problem Reports. 11149.